OmniGraffle is a unique program. To label it simply a drawing program is to short-sell its features. It's not PowerPoint, either - you wouldn't want to use it to create a full-fledged presentation. But for things like floor plans, organizational charts, and network diagrams, it's hard to beat OmniGraffle.

The program works off a concept of a palette of pre-made objects. You drag objects to the workspace, join them with others using lines and arrows, and then move things around as you see fit. Objects joined by arrows will remain joined as you drag them about; the arrow re-routes itself as ncessary.

You can use the pre-defined object palettes, create a new palette with your own objects, or download palettes of objects from OmniWeb. Anything can be an object on a palette, including photographs. This makes it easy to create realistic looking network diagrams, for example.

You'll need a pretty potent machine to take full advantage of OmniGraffle (it's pokey on my iBook/500 at times, but works fine on the G4/733), but if you have the horsepower, it's a great program!